This invention relates to hydraulic regulating valves and particularly to electro-hydraulic regulating valves.
Known electro-hydraulic regulating valves are composed of relatively delicate or critical components. An example of a control valve of this type appears in German Pat. No. 1,195,116. Such valves include a preamplifier stage which in turn regulates a main control stage with its own valve control members. The preamplifier stage is provided with regulating jets. The latter have very small orifice diameters which range in the order of 0.1 mm. This makes these jets extraordinarily sensitive to contamination and fouling, and oblige extremely fine filtering of the hydraulic fluid. Ultimately these factors complicate the construction of such valves, make adjustment difficult, and cause the valves to be expensive. While such valves may be operated at adequately high regulating speeds, they are not suited for extensive and rough treatment of the kind they would receive in motor vehicles.
An object of the invention is to improve electrohydraulic control valves and systems for their use.
Another object of the invention is to avoid the aforementioned disadvantages.
Another object of this invention is to provide an electrohydraulic control valve and a system therefor which avoids the aforementioned disadvantages, which nevertheless retains an equivalent fast regulation response, and yet displays a high degree of insensitivity to pressure variations and contamination of the hydraulic fluid.
Yet another object of the invention is to provide the aforementioned in an economic structure utilizing sturdy components.
Still another object of the invention is to furnish the above so that the valve arrangement is particularly well suited for mobile applications, such as use in motor vehicles.